Or you can go into the app bundle and modify the Info.plist, changing CFBundleExecutable from (for example) "Google Chrome" to the name of a new wrapper script that you put in MacOS. Here's a Python script that automates that for you (It actually makes a new app with symlinks). Run it with python linkapp.py<path to actual app> <where to put new app> in Terminal. When it asks you whether to create a wrapper script, answer y.